The purpose of the proposal is to determine if the reduction of the excess levels of hypothalamic norepinephrine, that we have demonstrated in obob mice, will attenuate the inordinate appetite and obesity problem in this mutant. The implications for certain forms of obesity, such as the Parder Willi syndrome are significant. We also plan to do a regional analysis of hypothalamic norepinephrine and dopamine to further localize the genetic defect. BIBLIOGRAPHIC REFERENCES: Central catecholamine turnover in genetically obese mice (obob). Lorden, Joan F., Oltmans, Gray A. and Margules, David L., Brain Research 117, 357-361, 1976. Central Noradrenergic Neurons: Differential effects on body weight of electrolytic and 6-hydroxydopamine lesions in rats. Lorden, Joan, Oltmans, G.A. and Margules, David L. Journal of Comparative Physiological Psychology, 90, 144-155, 1976.